Description

We established field plots in the Ouachita and Ozark Mountains of Arkansas and Oklahoma to quantify the impacts of oak decline on forest structure. Plots were identified as either high risk (red oak basal area > 20 square feet per acre) or low risk (red oak basal area < 20 square feet per acre). Red oak had the highest importance values on high-risk plots whereas shortleaf pine was the most important species on low-risk plots. Fifty percent of red oak density and 53 percent of red oak basal area were dead or dying on high-risk plots. In contrast, 20 percent of red oak density and 20 percent of red oak basal area were dead or dying on low-risk plots. Red oaks on all plots were killed regardless of tree d.b.h. Sapling and seedling regeneration on high-risk plots was dominated by nonoak, shade-tolerant species. In severely impacted areas, oak decline appeared to be accelerating a change in long-term species composition away from oak-dominated forests.